Substrate processing method, substrate processing apparatus, and substrate processing system

1. A method of processing a substrate, comprising: a production process of producing B(OH 3 ) or B 2 O 3 by bringing an ozone-containing aqueous solution into contact with a boron-based film in a substrate in which the boron-based film is formed on a film including a silicon-based film; a removal process of removing the boron-based film from the substrate by dissolving the B(OH 3 ) or B 2 O 3 produced in the production process in water; and a heating process of heating the ozone-containing aqueous solution, wherein the removal process includes dissolving the B(OH 3 ) or B 2 O 3 produced in the production process in the water contained in the ozone-containing aqueous solution, and wherein, in the heating process, the ozone-containing aqueous solution is heated immediately before being supplied to the substrate.

2. The method of claim 1 , further comprising: a holding process of holding the substrate in a horizontal posture; and wherein the production process includes bringing the ozone-containing aqueous solution into contact with the boron-based film by supplying the ozone-containing aqueous solution to the substrate held in the holding process using a supply part, the supply part being provided with a nozzle configured to discharge the ozone-containing aqueous solution and a nozzle arm configured to support the nozzle, the nozzle arm having a supply passage of the ozone-containing aqueous solution formed therein, wherein the heating process includes heating the ozone-containing aqueous solution flowing through the supply passage using a heating part provided in the nozzle arm.